[woah]

Are you talking about this?

    // in 2.4.1
    _([1, 2, 3]).forEach(function(n) { console.log(n); });
    // => logs each value from left to right and returns the lodash wrapper

    // in 3.0.0
    _([1, 2, 3]).forEach(function(n) { console.log(n); });
    // => returns the lodash wrapper without logging until `value` is called
    _([1, 2, 3]).forEach(function(n) { console.log(n); }).value();
    // => logs each value from left to right and returns the array

Seems that the only apps this change will break are those who are using side effects in a chain. Which is a pretty dubious choice, IMO. Especially given that Lodash is a "functional programming library".